<script setup>
defineProps({
    modelValue: String,
    count: Number
})
const emit = defineEmits(['update:modelValue', 'update:count'])
</script>

<template>
    <div>v-model 演示子组件 {{ modelValue }}</div>
    <button @click="emit('update:modelValue', '456')">子组件按钮</button>
    <div>{{ count }}</div>
    <button @click="emit('update:count', 999)">++</button>
</template>